给我提供一个用python写的河水分割的代码

以下是一个简单的用python实现河水分割的代码：

def riverSizes(matrix):
    sizes = []
    visited = [[False for value in row] for row in matrix]
    for i in range(len(matrix)):
        for j in range(len(matrix[i])):
            if visited[i][j]:
                continue
            traverseNode(i, j, matrix, visited, sizes)
    return sizes

def traverseNode(i, j, matrix, visited, sizes):
    currentRiverSize = 0
    nodesToExplore = [[i, j]]
    while len(nodesToExplore):
        currentNode = nodesToExplore.pop()
        i = currentNode[0]
        j = currentNode[1]
        if visited[i][j]:
            continue
        visited[i][j] = True
        if matrix[i][j] == 0:
            continue
        currentRiverSize += 1
        unvisitedNeighbors = getUnvisitedNeighbors(i, j, matrix, visited)
        for neighbor in unvisitedNeighbors:
            nodesToExplore.append(neighbor)
    if currentRiverSize > 0:
        sizes.append(currentRiverSize)

def getUnvisitedNeighbors(i, j, matrix, visited):
    unvisitedNeighbors = []
    if i > 0 and not visited[i - 1][j]:
        unvisitedNeighbors.append([i - 1, j])
    if i < len(matrix) - 1 and not visited[i + 1][j]:
        unvisitedNeighbors.append([i + 1, j])
    if j > 0 and not visited[i][j - 1]:
        unvisitedNeighbors.append([i, j - 1])
    if j < len(matrix[0]) - 1 and not visited[i][j + 1]:
        unvisitedNeighbors.append([i, j + 1])
    return unvisitedNeighbors

这个代码通过深度优先搜索遍历整个矩阵，对于每个遍历到的点，如果它是未访问过的河流，则从这个点开始继续搜索，直到搜索完整个河流，并记录河流大小，最终返回所有河流的大小。